EP0466080A1 - Fernbedienungsverfahren für Sender-Empfänger-Gruppen, insbesondere für die Rekonfiguration der Basisstationen eines zellularen Telefonnetzwerkes - Google Patents

Fernbedienungsverfahren für Sender-Empfänger-Gruppen, insbesondere für die Rekonfiguration der Basisstationen eines zellularen Telefonnetzwerkes Download PDF

Info

Publication number
EP0466080A1
EP0466080A1 EP91111356A EP91111356A EP0466080A1 EP 0466080 A1 EP0466080 A1 EP 0466080A1 EP 91111356 A EP91111356 A EP 91111356A EP 91111356 A EP91111356 A EP 91111356A EP 0466080 A1 EP0466080 A1 EP 0466080A1
Authority
EP
European Patent Office
Prior art keywords
filter
parameter
adjustment
frequency
ros
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP91111356A
Other languages
English (en)
French (fr)
Inventor
Jean-Pierre Bonin
Jacques Bursztejn
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Alcatel CIT SA
Alcatel Lucent NV
Original Assignee
Alcatel Telspace SA
Alcatel Transmission par Faisceaux Hertziens SA
Alcatel NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Alcatel Telspace SA, Alcatel Transmission par Faisceaux Hertziens SA, Alcatel NV filed Critical Alcatel Telspace SA
Publication of EP0466080A1 publication Critical patent/EP0466080A1/de
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
    • H03J7/02—Automatic frequency control

Definitions

  • the present invention relates to a device for adjusting the tuning frequency of a transmitter and a receiver, in particular for the remote reconfiguration of base stations of a cellular radiotelephone network.
  • the reconfiguration of such a transmission system is the operation which consists in modifying the working frequencies of a certain number of the radio channels constituting this system.
  • a base station controls a certain number of mobile terminals located in an area or "cell” covered by the base station. ; a "cellular network” is formed by the juxtaposition of a certain number of these cells.
  • a cellular network is associated with a whole management of the frequency distribution within this network.
  • This management is all the more complex as each base station comprises a large number of channels, therefore of separate transmitters each having its own frequency (typically, the base stations can comprise up to 16 channels and even more).
  • each of the transmitters and receivers of each of the base stations concerned consists in changing the central frequency of the corresponding transmit and / or receive channel.
  • This operation is carried out, for each channel, on two levels.
  • these filters are made up either of tuned resonant cavities, or of electronic systems comprising a variable impedance component (variable capacity diode for example).
  • the adjustment is made by moving one or more plungers, the depression of which in the cavity (or in the respective respective cavities, in the case of a filter with several poles) determines the frequency of tuning ; in the second case, the filter is adjusted by modifying the bias voltage of the variable capacitance diode.
  • the manual procedure consists in sending a technician to the site of the different stations to be reconfigured, with suitable measuring devices, and in adjusting the filters on the allocated frequencies.
  • This solution in addition to its cumbersome implementation (need for travel, cost, etc.) implies a very long overall reconfiguration time of the network, therefore its unavailability for at least several hours.
  • the automatic procedure consists in automatically adjusting the filters according to a programmed law, determined by a pre-calibration of each filter, giving the central tuning frequency of the latter as a function of the position of the stepping motor of adjustment of the plunger (s) (in the case of a mechanical tuning) or of the electrical quantity (current or voltage) of polarization applied to the diodes with variable capacitance (in the case of an electronic tuning).
  • This pre-calibration establishes a table, kept in memory, giving the positions of the plungers or the electrical control quantities for the various values of central frequency of the filter, and possibly taking into account an additional climatic variable, in order to take into account the working temperature, measured elsewhere, of the elements to be adjusted.
  • This method although it can be implemented automatically, has the drawback of being difficult to apply to the adjustment of narrow band filters such as those which are found in the base stations of cellular radiotelephony systems. the most recent, where the channels typically correspond to a bandwidth of the order of 500 kHz, in the 900 MHz band.
  • this adjustment mode does not take into account the drifts due, for example, to aging, due to the absence of any feedback control information that would allow the accuracy of the adjustment made.
  • One of the aims of the invention is to remedy these drawbacks by proposing a device allowing fully automatic implementation of the network reconfiguration.
  • the device of the invention is a device operating in closed loop, therefore with feedback making it possible to compensate for all possible misalignments, whether they are determinable (effects of temperature) or more or less random. (more or less significant aging of components, mechanical play, etc.).
  • the invention proposes to use various criteria making it possible to automatically adjust to a desired central operating frequency a microwave filter inserted in a transmitter / receiver.
  • These criteria may correspond to measurements made either from the signal normally transmitted, or from specific test signals which can be produced by the equipment to be adjusted itself, that is to say in the case of a cellular radiotelephony network, by the base station itself.
  • the equipment to be modified will operate as a measurement bench for its own modification.
  • said parameter is the standing wave ratio (ROS) at the input of the filter.
  • this parameter is the transfer function (if one places oneself in the frequency domain) or the impulse response (if one places oneself in the time domain) of the filter.
  • the filter for the measurement of the radioelectric parameter, it is in particular possible to apply to the filter a series of pure frequencies located in the band on which the filter must be adjusted, and / or on the sides of this band.
  • said parameter is the distortion rate, which we then seek to minimize in order to reach the agreement of the filter.
  • the measurement means can be made to measure several different parameters, the means for modifying the adjustment of the filter then being either controlled successively on these various parameters, or controlled by a composite criterion combining these various parameters.
  • the lessons of the invention can be extended to a system in which the reconfigured channel has several narrow filters tuned to the central working frequency, by example a filter on transmission and a filter on reception, or a plurality of successive filters connected in series and controllable separately.
  • ROS filter adjustment criterion
  • FIG. 1 shows the output stage of a transmitter, in which a transmission combiner 10 comprises a plurality of selective filters 11 tuned to respective frequencies Fi, F 2 ... F n whose outputs are combined on a common line 12 connected to the transmitting antenna of the base station.
  • the input ROS of each of the filters 11 can for example be measured at the level of the input circulator 13 of each channel, by means of a test socket 14 connected to a ROS measurement device, of the type in itself. even known.
  • This solution has the advantage, when there is already a circulator, of not adding any element to the transmission line.
  • Another possibility consists in using a directional coupler 15 added on the input line leading to each of the filters 11.
  • the measurement of the ROS obtained with this configuration has the advantage of being less linked to the intrinsic quality of the circulator, and therefore to reflect more precisely the value of the ROS at the input of the only filter 11.
  • the measurement of the ROS can be carried out either directly from the modulated signal, or - preferably - from a set of pure frequencies located in the band on which the filter must be adjusted. and on the sides of this strip.
  • the optimization criterion will be the minimization of the measured ROS.
  • the transmit combiner is a combiner with close channels, as illustrated schematically in Figure 2: indeed, in this case, the superposition of the channels at the crossover points leads to an interdependence of the settings filters, and it is therefore necessary to adjust each of them individually and very precisely.
  • the different pure frequencies can in particular be obtained by a wobbulation operated in the band on which the filter must be adjusted, as illustrated in FIG. 3.
  • This wobbulation can in particular result from a particular command from the local oscillator or from the emission synthesizer; the transmission of the normal modulated signal is then deactivated by an inhibition command appropriate to the modulator, and the VCO (voltage-controlled frequency oscillator) of the latter is appropriately controlled.
  • Another possibility consists, instead of making an adjustment with respect to a setpoint (the set of ideal stored ROS), to carry out an adjustment without setpoint, by optimizing the symmetry of the ROS values measured on either side of a point.
  • the adjustment can then be carried out by comparing the ROS values obtained at the frequencies fi and fs, or f 3 and f 7 , etc. and adjusting the setting so that these respective ROS values are as close as possible.
  • the symmetrization can also be done with respect to minima of the ROS curve located on either side of the central frequency.
  • the symmetrization will then be carried out on either side of the points A and A ', which are themselves, if the adjustment is exact, symmetrical with respect to the central frequency fs, that is to say with respect to the point O.
  • f i1 and f ; 2 are symmetrical frequencies on either side of the central frequency, or on either side of known local minima or maxima of the characteristic of ROS as a function of frequency.
  • FIG. 4 shows an example of an adjustment algorithm based on such a criterion.
  • step 100 a certain number of initializations are carried out, namely: selection of the channel (n) to be reconfigured, passage into wobbulation mode (inhibition of data transmission and specific control of VCOs) and setting of the synthesizers d on the different pure frequencies chosen.
  • This example of a flowchart corresponds to an adjustment of a filter consisting of a double resonant cavity or of two resonant cavities (two-pole filter) in which the adjustment is made by adjusting the penetration depth of respective divers; it will be noted that, as will be seen, the invention makes it possible to regulate one and the other of the plungers distinctly, whereas until now one was generally satisfied with regulating these two plungers simultaneously, the latter being linked together by an appropriate reduction.
  • the error function F is calculated at 108, for example from one of the relations (1) or (2) set out above.
  • step 109 If the value of this function is less than a predetermined threshold (step 109), the adjustment of the filter is considered to be completed (step 110).
  • step 113 it is determined (step 113) if you have reached the end of the setting with this plunger, in which case you will have to change plunger (steps 114 and 115) and resume the process with the other plunger. Otherwise, we simply change the direction of progression of the displacement of the plunger (steps 116 and 117) then we resume the same process by starting again in this reverse direction.
  • This transfer function can for example be measured using a directional coupler placed at the outlet of the filter.
  • this measurement mode can be difficult to implement in the case where the signals are recombined directly at the output of the emission filter, since it would then be necessary to provide microwave switches or relays to isolate the output of the filter to be adjusted from rest of combiner.
  • the measurements can be carried out either on the modulated signal or, preferably, on a set of pure frequencies, according to procedures similar to those which have been presented above for the ROS.
  • the signal used for this purpose will, depending on the characteristics of the filter, and more particularly its bandwidth, either a signal with the same characteristics as the signal normally transmitted, or else a signal having a digital bit rate adapted to the bandwidth of the filter.
  • This sampling provides an estimated value of the information transmitted, as well as an estimate of the error on this information.
  • FIG. 5 there is shown the block diagram of a base station configured so as to obtain distortion information by three different analysis modes; of course it is possible to use, as appropriate, only one or the other of these modes of analysis, which have been brought together in the diagram of FIG. 5 only for the convenience of the description.
  • the transmission combiner 10 comprising a series of narrow-band filters 11, there is the set 16 of baseband modulation and power transmission proper delivering the modulated signal (the modulating signal comprising for example digital data transmitted at a clock rate of frequency 1 / T S ) and a transmit antenna 17 radiating the signals of the different channels, combined on the transmit line 12.
  • the modulated signal comprising for example digital data transmitted at a clock rate of frequency 1 / T S
  • a transmit antenna 17 radiating the signals of the different channels, combined on the transmit line 12.
  • the reception part comprises, for its part, a receiver 18 receiving the signals picked up by the reception antenna 19 and a demodulator 20 of conventional type, which is in the example shown a quadrature demodulator comprising on each channel a mixer 21 receiving the frequency of the local oscillator, a low-pass filter 22, an amplifier 23 and an analog / digital converter 24.
  • a quadrature demodulator comprising on each channel a mixer 21 receiving the frequency of the local oscillator, a low-pass filter 22, an amplifier 23 and an analog / digital converter 24.
  • One of the channels gives an estimate of the signal I
  • the other channel gives an estimate of the signal Q.
  • These signals 1 and Q contain the transmitted information to which is added the distortion introduced by the transmission channel.
  • a first embodiment of the invention directly uses these signals 1 and Q, in their digitized form Î and Q delivered at the output of the demodulator 20, to calculate the distortion function, by means of a circuit 25 delivering a command Filter adjustment CF corresponding to this channel.
  • a second mode of implementation consists, when the station is equipped with a device called “time equalizer” 27, that is to say a device making it possible to reconstitute an ideal transfer function, to be used for the calculation of the distortion of the coefficients Ci delivered by this equalizer, this calculation being carried out in a circuit 28 delivering a control signal CF.
  • time equalizer a device making it possible to reconstitute an ideal transfer function
  • This temporal equalizer is in fact a transverse filter with self-adjusting variable coefficient (Ci).
  • the distortion function could for example be the following function:
  • Ci being the (complex) coefficients of the filter, noted C -n to C + m . If we manage to cancel such a function f (D), this means that the distortion is zero, and therefore that the filter tuning is perfect.
  • a third mode of implementation consists in using a radio test card 30 (which is often present in radio base stations) in order to provide, in addition to the test functions, a calculation of the distortion.
  • Such a card ensures, by means of a double frequency transposition, a loopback between transmission and reception. It comprises two local frequency synthesis oscillators 31, 32 controlled respectively by signals CS 1 and CS 2 and the outputs of which are applied to respective 0/90 ° couplers 33, 34 supplying a series of mixers 35, 36, 37 and 38 receiving at the input either the transmitted signal sampled by a directional coupler 39 downstream of the emission combiner (mixers 35 and 36) and delivering as output the signal transmitted to the receiver 18 via the directional coupler 40.
  • the information 1 and Q obtained at the output are applied to respective analog / digital converters 43 clocked at the frequency 2 / T s .
  • the digital values Î and Q obtained at the output are applied to a circuit 44 for calculating the transfer function, delivering information representative of the distortion to a circuit 41 producing the signal CF for controlling the filter of the corresponding channel.
  • the transposition synthesizers 31, 32 of the test card 30 are controlled on the channel of the station that one wants to adjust, and one can, for example, obtain the calculated distortion function, allowing to have the appropriate filter control information, from an estimate of the sampled impulse response of the global channel and by comparison of this response with an ideal response, the difference being due to the adjustment of the filter being adjustment.
  • two of the criteria developed above are used successively, namely the ROS criterion for a first coarse adjustment, then the distortion criterion for a second fine adjustment.
  • the algorithm used may be of heuristic type, the evolution of the error function (linked to the ROS in the first phase, to the distortion in the second phase) making it possible to determine the direction of the next control of the adjustment systems.
  • the filters are adjusted, distinguishing the “adjustment” of the channel and the “retouching” to be made to the adjacent channels of the made of this "adjustment", so that the fundamental rule according to which neighboring cells never have incompatible frequencies remains respected for all the channels of the network.
  • the system is first positioned in the "adjustment" position (step 201), then the M main channels to be adjusted are analyzed successively (step 202).
  • an adjustment is carried out in two stages, firstly from the ROS, using an algorithm similar to that explained above and illustrated with reference to FIG. 4 (step 203), then to a fine adjustment by using the distortion minimization criterion (step 204).
  • steps 203, 204 for example a first phase with use of the ROS criterion combined with the transfer function, then a second phase using the distortion criterion, or even a single phase with a composite criterion associating ROS and distortion.
  • step 209 When it has been determined (step 209) that all of the adjacent channels of the channel in question have been retouched, we then return to “adjustment” mode and the operation is repeated for the next main channel.
  • FIG. 7 represents a device making it possible to implement such an algorithm.
  • the modulator / transmitter 16 assembly there is the modulator / transmitter 16 assembly, the transmission combiner 11, the transmission antenna 17, the reception antenna 19, the receiver 18 and the demodulator 20, as well as the radio test card. 30, which can optionally be used to determine the distortion function of the transmission chain.
  • this control unit will itself be triggered and programmed by configuration orders sent by an appropriate remote transmission from a central control station sending to the control unit 50 the values of the frequencies of the new distribution plan and triggering the execution by the latter of the reconfiguration of the base station.

Landscapes

  • Mobile Radio Communication Systems (AREA)
  • Transceivers (AREA)
  • Selective Calling Equipment (AREA)
EP91111356A 1990-07-10 1991-07-08 Fernbedienungsverfahren für Sender-Empfänger-Gruppen, insbesondere für die Rekonfiguration der Basisstationen eines zellularen Telefonnetzwerkes Withdrawn EP0466080A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9008753 1990-07-10
FR9008753A FR2664767B1 (fr) 1990-07-10 1990-07-10 Dispositif de reglage a distance d'un ensemble d'emetteurs-recepteurs, notamment pour la reconfiguration des stations de base d'un reseau de radiotelephonie cellulaire.

Publications (1)

Publication Number Publication Date
EP0466080A1 true EP0466080A1 (de) 1992-01-15

Family

ID=9398546

Family Applications (1)

Application Number Title Priority Date Filing Date
EP91111356A Withdrawn EP0466080A1 (de) 1990-07-10 1991-07-08 Fernbedienungsverfahren für Sender-Empfänger-Gruppen, insbesondere für die Rekonfiguration der Basisstationen eines zellularen Telefonnetzwerkes

Country Status (6)

Country Link
EP (1) EP0466080A1 (de)
JP (1) JPH04280519A (de)
AU (1) AU8018191A (de)
CA (1) CA2046480A1 (de)
FI (1) FI913306A (de)
FR (1) FR2664767B1 (de)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0239219A2 (de) * 1986-03-19 1987-09-30 GEC-Marconi Limited Anordnungen hoher Leistung
EP0357876A2 (de) * 1988-09-05 1990-03-14 TELEFUNKEN Sendertechnik GmbH Verfahren zur Optimierung der Abstimmung eines Senders und Anordnung zum Durchführen des Verfahrens

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0239219A2 (de) * 1986-03-19 1987-09-30 GEC-Marconi Limited Anordnungen hoher Leistung
EP0357876A2 (de) * 1988-09-05 1990-03-14 TELEFUNKEN Sendertechnik GmbH Verfahren zur Optimierung der Abstimmung eines Senders und Anordnung zum Durchführen des Verfahrens

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
INTERNATIONAL SWITCHING SYMPOSIUM 1990, MAI 28 JUIN 1 1990, VOL. 6, PAGES 195-198, STOCKHOLM, &T NEXT GENERATION DIGITAL CELLULAR BASE STATION TECHNOLOGY" *

Also Published As

Publication number Publication date
AU8018191A (en) 1992-01-16
FI913306A (fi) 1992-01-11
FR2664767A1 (fr) 1992-01-17
JPH04280519A (ja) 1992-10-06
CA2046480A1 (fr) 1992-01-11
FR2664767B1 (fr) 1992-09-18
FI913306A0 (fi) 1991-07-08

Similar Documents

Publication Publication Date Title
EP0314101B1 (de) Radiofrequenzoptisches Übertragungssystem, besonders für Satellitenfunken
CA2096942C (fr) Procede de transmission numerique et recepteur a conversion directe
FR2602938A1 (fr) Ensemble d'abonne pour telephonie numerique sans fil; modem et dispositifs divers (synthetiseur de frequence...) pour cet ensemble
EP0606941B1 (de) Einrichtung zur Synchronisierung eines lokalen Trägers, in OFDM-Systemen
EP0039275B1 (de) Kombinierte Synthese- und Demodulationseinrichtung für Empfänger frequenzmodulierter Wellen und diese enthaltender Empfänger
FR2719437A1 (fr) Procédé et dispositif d'identification d'une voie de signalisation.
FR2711868A1 (fr) Dispositif de commande automatique en fréquence.
WO2011154466A1 (fr) Procédé d'utilisation d'une ressource fréquentielle partagée, procédé de fabrication de terminaux, terminaux et système de télécommunications
EP1079514A1 (de) Frequenzsynthesizer mit einer Phasenschleife
WO2001093415A1 (fr) Synthetiseur a modulation numerique
FR2530898A1 (fr) Dispositif d'accord a boucle a verrouillage de phase
EP0661816B1 (de) Einzelschleifenfrequenzsynthetisierer und einen solchen Synthetisierer enthaltende elektronische Anordnung
FR2691027A1 (fr) Circuit de sélection d'accord d'un récepteur radio.
FR2669165A1 (fr) Appareil et procede permettant de faire varier un signal dans l'emetteur d'un emetteur-recepteur.
EP0466080A1 (de) Fernbedienungsverfahren für Sender-Empfänger-Gruppen, insbesondere für die Rekonfiguration der Basisstationen eines zellularen Telefonnetzwerkes
CA1227548A (fr) Filtre actif hyperfrequence
EP0889619B1 (de) FSK-Modulator mit Phasenregelschleife
WO2006027427A1 (fr) Dispositif d'amplification du signal d'une antenne de reception
EP0790729A1 (de) Korrektur von Phasenrauschen eines PLL in einem PSK- oder QAM-Empfänger
EP0293287B1 (de) Testeinrichtung für einen Phasendemodulator mit Spreizspektrum
EP0504015A1 (de) FM-Empfänger mit gesteuertem Fangbereich
CA2308857A1 (fr) Dispositif et procede pour produire un signal filtre ayant une frequence donnee et emetteur hertzien emettant a une frequence etablie par un oscillateur reglable en frequence
FR2754657A1 (fr) Dispositif d'interfacage d'une liaison bidirectionnelle courants porteurs basse tension / radiofrequence
FR2557403A1 (fr) Emetteur-recepteur d'hyperfrequences a commutation electrique fonctionnant en duplex integral
EP0082750B1 (de) Empfangsanordnung für wenigstens zwei Radionavigationssysteme

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE ES FR GB IT LI NL SE

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: ALCATEL N.V.

Owner name: ALCATEL TELSPACE

17P Request for examination filed

Effective date: 19920629

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19940201